Extremely poor video quality

Discussion in 'SJ7 Star' started by EdwardTH, Aug 8, 2017.

  1. RBEmerson

    RBEmerson Humbled by events

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    This a link to the V1.18 video. The yellow center line, when enlarged, shows significant pixelation. At the end of the video, closing with the stopped motorcycles in front of my bike, the detail is terrible and there is far too much "color blobbing" instead.


    I used MediaInfo to display a file's technical values (resolution, fps, codecs, etc.). I compared this video, under FW V1.18, and an Alps video, under V1.15. While MediaInfo's summary says the files' information is almost 100% identical, the actual contents don't compare well.


    Maybe I didn't get a setting right, but AFAIK I duplicated all of the settings I used under 1.15.
     
    Last edited: Sep 25, 2017
  2. TonySosa

    TonySosa Administrator Staff Member

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    Youtube often compresses the video. can you please upload the files to google drive and forward to tony.sosa@gmail.com?

    We will try to pinpoint this issue.

    Thanks!
     
  3. RBEmerson

    RBEmerson Humbled by events

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    The YT video is quite accurate compared to the original footage. As with the Alps videos, they're transcoded to 4K to minimize YT's compression. (Obviously, transcoding does not add image detail. It does minimize YT compression artifacts)

    Compare the detail (I use grass next to the road as a benchmark) on the Kaunertal video with the Hawk Mountain video. There is definitely "speed streaking" in the Hawk Mountain footage, but look at the trees' leaves for a test of detail. The difference in image quality isn't as bad as the Sena Prism version, but it's there. Go to 10:45, where the cruisers are in sight but not close (100-200 meters???). The detail just isn't as good as with V1.15. Look at the yellow center line and the "jaggies" (pixelation) are there. (There are places where a new line is painted over an older, faded line - ignore that).

    Again, going back to the Kaunertal video, distant objects remain clear. There is a very faint pale stripe along the edge where the mountains are contrasted with the sky. I recognize this as a common image processing artifact. With V1.18, this line is very distinct compared to V1.15. That's common with over-processing for sharpness.

    Finally, I do not see this as a lens issue. Look at the earlier screen grabs for demonstrations of how well the lens functions. The frame with the cobblestone road is a particularly good example of the lens' sharpness. Also, I don't see any obvious traces of chromatic aberration (blue or yellow edges to objects).

    Regarding the video file, it's 43Gb. I've tried zipping similar large files, in hopes of avoiding processing by Dropbox, etc. Unfortunately, they can open the zip and process the contents (which raises troubling questions about that interference, but that's a discussion for another forum). The only way I can get the source and edited video to you is by mailing an SD or USB stick. PM me if you want to look into doing this.
     
  4. Damian Holt

    Damian Holt Moderator

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    Hi, I’m still considering purchasing this camera but I get a little concerned when I read negative comments. Is it worth a purchase or am I going to have issues with it going forward?
     
  5. RBEmerson

    RBEmerson Humbled by events

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    Buy it!!! Honest. What you're seeing here is a mix of "sure would be nice" and "I'm having a problem with something". In my case, the imagery from earlier firmware is IMHO crisper. I'm commenting about the change because SJCam listens to their customers. Which is more than I can say for my last camera. Anyway, maybe I'm just being picky, and maybe something really has changed. If I don't report what I think happened, and there is a problem, it won't get fixed. If it's something I did, if I don't get feedback, I won't improve my work.

    I was dissatisfied with my previous camera (see an earlier Hawk Mtn video linked in here somewhere). The SJ7's specs, notably the sensor and digital signal processor's specs, made the SJ7 a very attractive choice. I think my videos from the Alps show how good it can be.

    The first camera I received was effectively DOA. I was not a happy camper, not in the least. Long story short, I looked at other options, found nothing as good as the SJ7's specs, rolled the dice on a second camera and... ding! ding! ding! We have a winner!

    Would I buy the SJ7 knowing what I know now? Yes. But... I wouldn't leave it to days before a trip. SJCam, IMHO, needs to tune up their QC. Odds are you're new camera will be fine, but leave room in your plans for dealing with a return/replace cycle.

    Finally, remember that it's the (relatively) few unhappy people who post complaints, while the many happy people are off doing something with whatever item is in question and they don't have time for posting. It looks like lots of unhappy people and not many happy people, which, most likely isn't the case.

    DISCLAIMER: I do not work for SJCam or a distributor or retailer. I have no connection with anyone in the supply chain. I'm just a loud-mouth customer. ;)
     
  6. Troy

    Troy Administrator Staff Member

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    @RBEmerson is just a loud-mouthed customer who just so happened to be really awesome :)

    Yea, the first few stuff that people are unclear about had to go through a bit of transition. Now with the new firmware out, and some very minor hardware changes, things are looking pretty good. SJCAM went through the firmware suggestions found somewhere in these forums, and got many of them right.
    Keep your suggestions coming!
     
  7. Damian Holt

    Damian Holt Moderator

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    Thanks for your detailed reply Emerson, very much appreciated.

    I’ve been toying between garmin gopro or sjcam and watched hours of footage already trying to make my mind up.

    I fully understand what you mean regarding negative posts, I’ve been a garmin watch user for 3 years and there are quite a few negative posts on their forums, however I’ve been happy and don’t experience the issues they do or I’ve done my research and I’m aware of the limitations.

    May just have made my mind up finally
     
  8. RBEmerson

    RBEmerson Humbled by events

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    @Damian: IMNSHO, unless a GoPro camera does something that you really, really need, the SJ7 will do it at least as well, and save money, too. Two related comments: 1) the camera isn't sealed as well as it might be. If you're going to shoot, outdoors, with the internal battery, use the included watertight case. 2) If you're going to shoot outdoors with an external battery, buy the watertight external battery case from SJCam.

    @Troy: The MK II version of the SJ7 really does need at least some degree of dust and moisture protection without having to resort to a full-on case for just a misty day or when there's a bit of dust blowing around.
     
  9. Christian Holt

    Christian Holt New Member

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    Emerson, a month has passed, what did you end up doing? Did you go back to 1.15 or did you stick with 1.18?
     
  10. RBEmerson

    RBEmerson Humbled by events

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    I just updated to the revised 1.18 (22 Sept. release date). I haven't had a chance to test the camera since then. I'm hoping I can get in a long ride towards the end of the coming week. That'll give me a chance to see what happens with the revised firmware.
     

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